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loft <br /> -23- <br /> The only ground water aquifers that have the potential to be impacted by <br /> mining (the aquifers discussed above) are those used by the applicant. <br /> Several mine production wells are completed into the alluvial aquifer of <br /> Coal Creek. See Table III-C-3 of the permit application for a <br /> description of all private water wells in the area. No wells are known <br /> to be completed in the coal-bearing strata of the iMesaverde Group in the <br /> vicinity of the mine. <br /> The applicant proposes to mine both the Coal Basin coal seam ("B" seam) <br /> and the Dutch Creek coal seam ("V" seam) by underground mining methods <br /> (see Figure III-0-1 of the permit application for stratigraphic <br /> relationships). The mine entries will be located near the outcrop of the <br /> seams. No significant physical disturbance of adjacent strata will occur <br /> as a result of the mine entries. �d <br /> v <br /> In addition, the applicant proposes to construct a tunnel which will <br /> connect the 2 seams currently being mined. This tunnel will be used to �,,• <br /> more efficiently transport coal out of the mines. The tunnel entry will <br /> be located in the underlying Mancos shale formation and will continue up <br /> the stratigraphic section until it intersects with the Dutch Creek coal <br /> seam. It will cut through 3 sandstone units that are considered <br /> potential aquifers. They are, in stratigraphically ascending order, the <br /> Cozzette, Rollins, -and Middle sandstones (see Figure II-D-1 of the <br /> permit application) . The waste rock generated during th ' construction <br /> of this tunnel will be disposed of near Uutch Creek <br /> k-Apou Jk .,,#tco 4-4j;" 4 <br /> 4+� he mines dewater the co sda nd adjacent strata as part of normal rS <br /> 'operations. This dewat rocess will cause water levels in some <br /> aquifers to be lowered. The decline in water levels should not exten� cs <br /> ur <br /> more than a mile from the edge of the mine workings. This effect should <br /> be temporary in nature. When mining is completed, the water levels in ,y <br /> the aquifers should return to pre-mining elevations. <br /> Other effects on ground water will be a slight mixing of ground waters <br /> from previously unconnected aquifers as a result of the proposed rock <br /> tunnel and a slight degradation of alluvial eater from the coal <br /> processing waste pile and the rock tunnel waste pile. None of these <br /> impacts are expected to cause material damage to ground waters in the <br /> Coal Basin area. For further discussion of impacts, see Section VII of <br /> this document; Probable Cumulative Hydrologic Impacts. <br /> Ground water quality and water levels are measured in the 12 alluvial <br /> wells shown on Map IV-C-1 of the permit application. Water levels in n <br /> these wells are measured monthly and the water is sampled quarterly. y,i► <br /> Ground water quality data collected from four of these wells are LLl <br /> presented in appendix III-E-2, Figure III-E-2, and Table III-E-1 of the 1 1 <br /> permit application. An additional eight monitoring 4ells were completed <br /> and monitoring commenced in Uctober, 1982. 1 <br /> The Uivision has reviewed the ground water monitoring program proposed by SUP tj <br /> the applicant. The requirements of the monitoring are oriented towards �Itc <br /> verifying the probaole hydrologic consequences discussed in Secti n 'III <br /> � �� <br /> o C�&4 <br /> �r N � <br />